package com.yangwudi.filter;

import com.yangwudi.utils.JwtUtils;
import io.jsonwebtoken.Jwts;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;

import java.io.IOException;

//<----------------------------------过滤器Filter和拦截器Interceptor实现功能相同，两者二选一保留即可----------------------------------->

@Slf4j
//@WebFilter(urlPatterns = "/*")
public class TokenFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1. 获取请求路径
        String requestURI = request.getRequestURI();//  /login

        //2. 判断是否是登录请求，如果路径中包含/login，说明是登录请求，则放行
        if (requestURI.contains("/login")) {
            log.info("登录请求，放行");
            filterChain.doFilter(request, response);
            return;
        }

        //3. 获取请求头中的token
        String token = request.getHeader("token");

        //4. 判断token是否存在，如果不存在，说明用户没有登录，返回错误信息（响应401状态码）
        if (token == null || token.isEmpty()) {
            log.info("令牌为空，响应401");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);//401状态码
            return;
        }

        //5. 如果token存在，校验令牌，如果校验失败 -> 返回错误信息（响应401状态码）
        try {
            JwtUtils.parseToken(token);
        }catch (Exception e){
            log.info("令牌非法，响应401");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);//401状态码
            return;
        }
        //6. 校验通过，放行
        log.info("令牌合法，放行");
        filterChain.doFilter(request, response);
    }
}
